diff --git a/skills.sh.json b/skills.sh.json
index 4b0e943..bfe4e89 100644
--- a/skills.sh.json
+++ b/skills.sh.json
@@ -1,6 +1,6 @@
 {
-  "$schema": "https://skills.sh/schemas/skills.sh.json",
-  "groups": [
+  "$schema": "https://skills.sh/schemas/skills.sh.schema.json",
+  "groupings": [
     {
       "title": "UI & Layout",
       "description": "Responsive Flutter layouts, constraint debugging, and app localization.",
diff --git a/tool/generator/README.md b/tool/generator/README.md
index d637f3e..ff3f022 100644
--- a/tool/generator/README.md
+++ b/tool/generator/README.md
@@ -144,8 +144,8 @@ The default configuration file is located at `resources/flutter_skills.yaml`. It
 When adding, renaming, or deleting a `flutter-*` skill in `skills/`:
 
 1.  **Update `README.md`**: Run `dart run skills update-readme` (or update the `Available Skills` table in the root `README.md`) so the table matches the `flutter-*` directories in `skills/`.
-2.  **Update `skills.sh.json`**: Add, rename, or remove the skill entry under `groups` in the root `skills.sh.json` file ([skills.sh documentation](https://www.skills.sh/docs/customize)).
-    *   Only `flutter-*` skills belong in `groups` (synced `dart-*` skills are canonical in `dart-lang/skills`).
+2.  **Update `skills.sh.json`**: Add, rename, or remove the skill entry under `groupings` in the root `skills.sh.json` file ([skills.sh documentation](https://www.skills.sh/docs/customize)).
+    *   Only `flutter-*` skills belong in `groupings` (synced `dart-*` skills are canonical in `dart-lang/skills`).
     *   Because `skills.sh` retains historical skill slugs from install telemetry after a skill is renamed or deleted in Git, `"notGrouped": "bottom"` at the end of `skills.sh.json` automatically demotes any retired skill slugs and ungrouped `dart-*` copies into an `Other skills` section at the bottom of the page.
 3.  **Verify**: Run `dart test` in `tool/generator` (`test/lint_skills_test.dart` verifies that `skills.sh.json` and `README.md` match the `flutter-*` directories in `skills/`).
 
diff --git a/tool/generator/test/lint_skills_test.dart b/tool/generator/test/lint_skills_test.dart
index 6c29d08..fa426fa 100644
--- a/tool/generator/test/lint_skills_test.dart
+++ b/tool/generator/test/lint_skills_test.dart
@@ -11,7 +11,7 @@ import 'package:skills_lint/skills_lint.dart';
 import 'package:test/test.dart';
 
 const String _expectedSkillsShSchema =
-    'https://skills.sh/schemas/skills.sh.json';
+    'https://skills.sh/schemas/skills.sh.schema.json';
 const int _maxGroupTitleLength = 30;
 
 void _validateGroupTitle(Object? title) {
@@ -80,11 +80,19 @@ void main() {
         jsonDecode(skillsShFile.readAsStringSync()) as Map<String, Object?>;
     expect(skillsShJson[r'$schema'], _expectedSkillsShSchema);
 
+    // The skills.sh schema sets additionalProperties: false, so unknown keys
+    // (such as a misspelled "groups") make skills.sh ignore the file.
+    expect(
+      skillsShJson.keys,
+      everyElement(isIn([r'$schema', 'groupings', 'notGrouped'])),
+    );
+
     // Setting notGrouped to "bottom" instructs skills.sh to render any skill
-    // not listed in "groups" (including previously deleted/renamed skill slugs
-    // retained in skills.sh install telemetry and synced dart-* copies) under
+    // not listed in "groupings" (including previously deleted/renamed skill
+    // slugs retained in skills.sh install telemetry and synced dart-* copies)
+    // under
     // its built-in "Other skills" heading at the bottom of the repository page
-    // (the schema only accepts "top", "bottom", or "hidden", and does not
+    // (the schema only accepts "top" or "bottom", and does not
     // support a custom label).
     expect(skillsShJson['notGrouped'], 'bottom');
     expect(skillsShJson.keys.last, 'notGrouped');
@@ -92,11 +100,15 @@ void main() {
     // 3. Validate each group's title, description, and unique skill
     // identifiers, and ensure that all grouped skills exist as flutter-*
     // directories in skills/ (without typos or missing skills).
-    final groups = (skillsShJson['groups'] as List<Object?>)
+    final groups = (skillsShJson['groupings'] as List<Object?>)
         .cast<Map<String, Object?>>();
     expect(groups, isNotEmpty);
 
     for (final group in groups) {
+      expect(
+        group.keys,
+        everyElement(isIn(['title', 'description', 'skills'])),
+      );
       _validateGroupTitle(group['title']);
       _validateGroupDescription(group['description']);
     }